Coating composition.



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MAURICE MALAN DURKEE, OF SAVANNAH, GEORGIA.

COATING COMEOSITION.

No Drawing.

To all whom it may concern 7 Be it known that ll, MAURICE MALAN DUR- mm, a citizen of the United States, residing at Savannah, in the county of Chatham and State of Georgia, have invented a certain new and useful Coating Composition, of which the follmving is a specification.

My present invention pertains to an improved mixture or composition for rendering containers oil-proof, and is intended a more especially as a protective coating for use upon paper or other material which has a natural atlinity for oil or grease,

Paper cartons have come into extended use,- and various materials, some of which are edible and have as their base modified vegetable oils, have likewise come into use. This condition has brought about the necessity for treating such cartons with an oilimpervious coating, which coating must, of course, be permanent, in that'it is not affected by the oil, is more or less flexible, is firmly adherent, and, at the same time, inert to the oily material or substance, and not deleterious to health. Furthermore, the coating must be such that the oily material will not be affected thereby. To this end I have found that a composition or mixture containing a colloidal substance (glue or food gelatin), dextrose or glycerin, water and preferably, as a hardening agent, hexamethylenetetramin, may be advantageously employed.

The following formula has produced the best results: 17.0% glue, 13.0% dextrose, 0.4% hexalnethylenetetramin, 69.6% water.

The dextrose and hexamethylenetetramin are dissolved in half the volume or quantity of water used, a steam or water bath being employed to produce the necessary heat. The glue is soaked in the other half of the water for about an hour, the time depending upon the character of the glue employed; and when these two steps are complete, the two portions are mixed and melted over a bath, the temperature being brought to from 65 to 70 C. Preferably, the glue is melted over the hot bath before mixing the other constituents therewith.

Specification of Letters Patent.

Patented July 25, 1916.

application filed December 7, 1915. Serial No. 65,528.

The mixture thus produced is applied while hotto the container to be oil-proofed, the container being filled and allowed to stand about one minute. It is then drained and permitted to dry, which usually requires about two hours. The mixture may also be sprayed upon the container to produce the coating, or it may be applied with a brush, or in any other suitable manner.

Containers thus treated are found to be oil-proof, the hexamethylenetetramin hardening the glue and rendering it proof against the attack of the oil, while the dextrose so modifies the glue as to render it flexible and thus prevents cracking of the surface.

As above noted, food gelatin may be employed in place of glue, and glycerin instead of dextrose, and when glycerin is used it will be present in approximately 9%.

The working range of all the substances would be included in the following percent: ages: glue or food gelatin 10 to 25% of whole, dextrose 10 to 25% of whole, glycerin 5 to 15% of whole, hexamethylenetetramin O to 2% of whole.

The hexamethylenetetramin in the composition, acting upon the glue or gelatin, renders the coating tough. Its presence, while preferred, is not, however, absolutely essentia Having thus described my invention, what I claim is:

1. A coating composition for rendering materials impervious to fatty materials, comprising a colloidal substance dissolved in water; dextrose; and hexamethylenetetramin, in substantially the proportions-described.

2. A coating composition for rendering materials impervious to fatty materials, comprising the following substances in substantially the proportions stated, to wit: glue 17.0%, dextrose 13.0%, hexamethylenetefi ramin 0.4%, and water 69.6%.

In testimony whereof have signed my name to this specification. 

